Removed admin app, bug fixes on signature and new WResponse
Fixes a bug on admin/user/groups linked to new architecture
Recoded WResponse mode (m, v, mv) and Route calculation done in WRoute
Removed useless WResponseSerialize
Tiny bug fix in WMain
Save previous mode in routing
Removed AdminController from user app
Merge pull request #83 from Creatiwity/delete-admin-app

Bye bye admin, WResponse rebuilt and WRoute clear
Allows form to be sent from external application

Signature's check is not a necessary condition: the system will now take
into account the form's action.
Added an algorithm to send a 404 error for physical files not found
User/login receives parameter
Merge remote-tracking branch 'origin/0.4' into admin-bootstrap-3